BR0114654B1 - plastic container having a carbon-treated inner surface for non-carbonated food products. - Google Patents

Abstract

A method of manufacturing a molded container coated with a carbon coating, desirably blow molded or extrusion molded, said container having barrier properties and including an upper wall portion having an opening, an intermediate sidewall portion positioned beneath the upper wall portion, and a base portion positioned beneath the intermediate sidewall portion to support the container. The container includes a molded first layer having an inner surface and an outer surface formed from high density polyethylene, and a carbon coating is formed on the inner surface of the first layer and adhered thereto and substantially coextensive with the first layer, wherein said carbon coating has a thickness of less than about 10 microns.

Description

Plastic container having a carbon-treated inner surface for non-carbonated food products.

The present invention relates to plastic containers, preferably for non-carbonated high density polyethylene (HDPE) based food products. More particularly, the present invention relates to HDPE-based molded plastic containers having barrier properties and a carbon-coated inner surface.

It is highly desirable to provide plastic containers with barrier properties, and it is also highly desirable to provide plastic containers using HDPE.

HDPE is more like a regular crystal than ordinary amorphous entanglement of low density polyethylene (LDPE) polymer chains. Also, HDPE is stronger and more inflexible than LDPE. However, HDPE generally has no barrier properties and has poor oxygen permeation ratios. Thus, despite the willingness to use HDPE, as it is economical, use of such material has not been practical.

It would be particularly desirable to use HDPE for containers for non-carbonated food products such as beverages because of its low cost and desirable properties if one could discern an effective and low cost way to overcome the high porosity of this material.

Multilayer plastic containers are commonly used for packaging items in a wide range of fields, including food and beverage products, medicine, health and beauty, and home use.

Plastic containers are known to be easy to shape, cost-effective and generally suitable for many applications. Multilayer containers provide the benefit of being able to use different materials in each layer, where each material has a specific property suitable for performing the desired function.

Because plastic containers may allow low molecular weight kegases, such as oxygen and carbon dioxide, to slowly permeate through their physical configurations, the use of plastic containers sometimes proves to be less desirable when compared to containers formed of other less permeable materials. like metal or glass. In most applications, product life as content operability is directly related to the packaging's ability to effectively withstand such molecular permeation. In the case of non-carbonated beverages such as juices, oxygen in the atmosphere surrounding the container may gradually permeate into the container through the plastic walls of the container to reach the interior of the container and deteriorate the contents. A highly porous container such as HDPE1 may allow rapid deterioration of the taste of the container contents.

To support some of the aforementioned issues, plastic container manufacturers have used various techniques to reduce or eliminate absorption and / or permeability of such gases. Some of the most common techniques include: increasing the thickness of all or portions of the container walls, incorporating one or more barrier layers into the wall structures; including an oxygen scavenger or reactive material within the container walls; and application of various coatings to the inner and / or outer surface of the container.

However, a number of conventional barriers and / or sweeping materials do not effectively decrease permeation through a highly porous container wall, especially for extended periods of time. In addition, there are usually other practical issues associated with most conventional techniques, most commonly, increased material cost, and / or production inefficiencies.

In recent times, the use of plastics has become a social designation article. Recycling has become an increasingly important environmental issue, and a number of regulations by governments and enforcement authorities continue to address the issue. In a number of jurisdictions, legislation regarding the collection, return and reuse of plastic containers has been considered as well as has already been enforced.

In addition, HDPE is a particularly desirable material, especially for non-carbonated food products such as beverages, due to its desirable properties. For example, it has high strength and is low cost; It can be correctly used with colored concentrates to provide an attractive color to the product that will also reduce or eliminate the harmful effects of ultraviolet light. In addition, it can be used effectively with a wide variety of colored concentrates; It has good processability and good contraction properties.

Thus, there is a need in the industry and it is an object of the present invention to provide an HDPE-based plastic container, especially that is suitable for containing non-carbonated beverages such as juices, and to provide an acceptable level of efficiency when compared to commercial containers formed with alternative materials. Another need exists for a method for producing such containers at high commercial volume ratios using conventional equipment.

It is still an object of the present invention and the need to provide an HDPE-based container that has barrier properties and to minimize or avoid the high cost of inconvenience of conventional multi-layer plastic containers. It is still a further goal to achieve this with a cost effective, commercially viable process, and an effective product. It has been found that the above objectives and advantages are correctly achieved in accordance with the present invention.

Recognizing the problems and issues associated with conventional multilayer plastic containers, especially those used for containing non-carbonated food products, especially beverages, a plastic container having improved HDPE-based gas barrier properties is advantageously provided herein. A container constructed in accordance with the principles of the present invention provides several advantages over those previously available. Such advantages are generally configured through the use of the desired HDPE and a carbon coating on the inner surface of the container. It is a significant advantage that the container of the present invention may desirably also include oxygen sweepers and may have a multilayer configuration. In addition, improved container may be produced using conventional processing techniques and manufacturing equipment.

An important aspect of the present invention is to have effective barrier properties in the present container with the functional and commercial benefits associated with having a container including the desired HDPE. Moreover, the ease of recycling subsequent to the container produced in accordance with the principles of the present invention makes the practice of the invention extremely advantageous. Moreover, the present invention provides the additional advantage of allowing the producer to vary the material positioning and wall thickness in a controlled manner. in any position along the vertical length of the inner and / or outer layers of the container. In accordance with the principles of the present invention, a container is provided which is particularly suitable for non-carbonated food products such as can be blow molded or extruded molded having an upper wall portion, an intermediate side wall portion positioned below the portion. upper wall, and a base portion positioned below the intermediate sidewall portion, the base portion being adapted to support the dependent recipient or independently. The container includes a first molded layer having an inner surface and an outer surface formed of high density polyethylene and a carbon coating formed adjacent and desirably on and adhered to and substantially equal to the inner surface of the first outer layer. In a preferred embodiment, the thickness of the first layer is controllably adjusted along its vertical length. If desired, the first layer may also include additional barrier materials and / or oxygen scavengers / reactive materials incorporated therein.

According to the principles of the present invention, the container may include a second layer adjacent to the first layer, wherein the second layer is adjacent to at least one of the inner surfaces of the first layer and outer surfaces of the first layer to provide a highly desired multilayer container.

The HDPE used in the present invention has an above density of about 0.940 grams / cm3.

The container of the present invention is particularly suitable for use with non-carbonated products such as foodstuffs, but may also be used for products which advantageously include injection of gases within themselves, such as CO2 or nitrogen.

Further and further advantages are readily apparent from the following detailed description of how best to conduct the invention when taken in connection with the accompanying drawings where, for purposes of example and example, embodiments of the present invention are described.

The present invention will be more readily understood by considering the accompanying drawings, where:

Figure 1 is an elevational view of a container according to the principles of the present invention;

Figures 1A, 1B and 1C are enlarged cross-sectional views of various areas of the container where the relative thicknesses of the container-forming layers are shown;

Figure 2 is a partially broken elevation view of an example of a multilayer preform;

Figure 3 is a partially broken elevation view of another example of a multilayer preform;

Figure 4 is an elevational view of a container according to the principles of the present invention;

Figures 5, 6 and 7 are enlarged cross-sectional views of the container showing the relative thicknesses of the layers forming the container;

Figure 8 is a partially broken elevation view of an example of a preform;

Figure 8 is a partially broken elevation view of an example of a preform; and

Figure 9 is a partially broken elevation view of another example of a preform.

Referring now, in the detailed drawings, similar numerical and literal references indicate similar elements, there is nafig. 1 is an elevational view of a container 10 constructed in accordance with the principles of the present invention. The container (10) typically includes an upper wall portion (12) including an opening (13); an intermediate sidewall portion (14) positioned below the upper wall portion (12); and a base portion (16) positioned below the intermediate sidewall portion (14). The base portion 16 is adapted to support the container 10 dependently, ie where another object such as a base cup (not shown) is used, or independently, ie where no other object is required to hold the container. container standing on a flat generic surface. In a preferred embodiment, the container 10 is supported by a self-supporting base formed by an internal depression 18 as sampled in FIG. 1, although other base configurations known in the art may be used.

Referring to FIGS. 1A - 1C depicting enlarged detailed views of areas 1A, 1B and 1C respectively of FIG. 1, the container (10) includes: a) a molded inner layer (20) having a vertical length and an inner surface (22); b) a molded outer layer (24); and c) a verticalcentral axis A. The inner surface (22) of the molded inner layer (20) is at least partially coated with a thin layer or carbon film (26). While complete encapsulation of the inner layer (20) by the outer layer (24) is not required, it is preferred that the molded outer layer (24) be substantially extended equal to that of the inner layer (20) providing structural support to the recipient walls (10).

The molded inner layer 20 is comprised of thermoplastic material. The following resins may be used as plastics materials for the inner layer (20): polyethylene resins, polypropylene resins, polystyrene resins, cycloolefin copolymer resins, polyethylene terephthalate resins, polyethylene naphthalate resins, copolymer resins ethylene (vinyl alcohol) resins, poly-4-methylpentene-1 resins, polymethyl methacrylate resins, acrylonitrile resins, polyvinyl chloride resins, polyvinylidene chloride resins, deacryl styrene nitrile resins, styrene-butadiene acrylonitrile, polyamide resins, polyamide-imide resins, polyacetal resins, polycarbonate resins, polybutylene terephthalate resins, ionomer resin, polysulfone resin, fluorine ethylene resin, and the like. When food content is involved, the inner layer (20) is preferably formed of virgin polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and / or depolyethylene terephthalate and polyethylene naphthalate blends. However, other thermoplastic resins may also be used, particularly those approved for food contact.

The molded outer layer 24 is comprised of HDPE and provides the main volume of the container. In a preferred embodiment, the inner layer 20 has a wall thickness taken along its vertical length of 0.5 mils. 5 mils (0.0127mm to 0.127mm) and more preferably between 1 and 2 mils (0.0254mm to 0.0508mm). As shown in fig. 1 and fig. 1A, 1B and 1C, the inner layer thickness can be varied along the vertical length. In this way, different portions of the container 10 may have variably controlled thicknesses along the vertical length, providing improved material utilization and increased design flexibility. For example, the thickness of the inner layer 20 positioned at the upper portion 12 (as shown in Fig. 1A) may be thinner than the intermediate sidewall portion (14) (as shown in Fig. 1B). .

Similarly, the thickness of the inner layer 20 in the base wall portion 16 (as shown in Fig. 1C) may be thinner than the thickness of the same layer in the intermediate side wall portion 14 (as shown in Figure 1C). Fig. 1B).

Taking an aspect of the present invention, the inner layer comprises less than 0.60 by weight of the total weight of the container (10), preferably less than 0.30 of the total weight of the container (10), and more preferably less than about 0.10. 15 of the total weight of the container (10). The ability of the present invention to use an exceptionally thin inner layer (20) - particularly as compared to other conventional multilayer containers - can provide significant economic advantages, and encourages present invention containers where the bulk is made of inexpensive HDPE.

As already mentioned, the inner surface (22) of the inner layer (20) is coated with a thin carbon layer (26) which provides increased barrier properties to the container (10). In a preferred embodiment, the carbon coating (26) is comprised of a highly hydrogenated amorphous carbon that is doped with nitrogen. The thickness of the carbon lining 26 is less than about 10 μιτι and the weight of the lining 26 is less than about 1/10 000 of the total weight of the container. An important aspect of the present invention is that only about 3 mg of carbon coating 26 is required to treat a 500 cc plastic container. Moreover, despite the remarkable thin thickness of the carbon coating (26), the amount of barrier protection achieved is quite significant and the protection against oxygen and carbon dioxide permeation is favorable compared to the protection found in metal cans or glass bottles.

The molded outer layer (24) of HDPE comprises at least 0.40 weight by weight of the total weight of the container (10) but may comprise more than 0.90 by weight of the total weight of the container (10), if desired.

In a preferred embodiment, the outer layer 24 has a wall thickness taken along its vertical length which is in the range of 6 to 23 mils (0.1524mm to 0.5842mm). As shown in fig. 1 and figs. 1A, 1B and 1C, the outer layer thickness may also vary separately and independently along its vertical length. In this way, different portions of the container (10) - (taken perpendicular to the central vertical axis A) may have different inner layer thicknesses, different outer layer thicknesses, and / or different overall thickness measurements; all in / by project. For example, the thickness of the molded outer layer 24 positioned at the upper portion 12 - as shown in fig. 1A - may be much thicker than the intermediate sidewall portion 14 - as shown in FIG. 1B. Similarly, the thickness of the outer layer 24 in the base wall portion 16 - as shown in fig. 1C - may be thicker than the thickness of the same layer in the intermediate sidewall portion 14 - as shown in FIG. 1B. Because the molded outer layer (24) is made of the less expensive HDPE material that does not directly contact the contents of the container (10), a less expensive material may be used to form a number of the structurally integrated components of the container, such as the neck flange. and the outer threads 32 shown in fig. 1 and fig. 1A.

While it is often unnecessary, and can be complicated by the recycling process, in special applications, the inner layer (20) and / or outer layer (24) may still include additional barrier materials, and / or oxygen scavengers or reaction materials (not shown). which are commonly known in the art. Examples of some of the most common barrier materials include saran, vinyl ethylene alcohol copolymers (EVOH), and acrylonitrile copolymers such as Barex. The term saran is used in its normal commercial sense to contemplate polymers made for example from polymerization of vinylidene chloride and vinyl chloride or methyl acrylate. Additional monomers may be included, as is well known. Vinylidene chloride polymers are often the most commonly used, but other materials such as oxygen barriers are well known. Oxygen-sealing materials may include materials marketed for this purpose by various oil companies and resin manufacturers. A specific example of such material is marketed under the trademark of AMOSORB and is commercially available from Amoco Corporation.

Another significant advantage of the present invention is the ability to provide significant barrier properties, incorporate a high content of desired HDPE material, and to be advantageous to present day recyclability. The inner layer 20 and the outer layer 24 are both comprised of plastics material and can be readily recycled. Unlike a number of other barrier materials often used in connection with multi-layer containers which may make it difficult to separate, the carbon coating (26) of the present invention has no impact on the recycling of the plastic materials of which container (10) is composed.

The present invention includes the additional advantage that it is capable of providing a container (10) with enhanced barrier properties that can be used to support food products. Plastic containers having an inner surface treated with an amorphous carbon film have been approved for contact with food products by Technische National Onderzoek, the European Economic Community-accredited standard organization. United States Food and Drug Administration (USFDA) approval is currently in process.

The container (10) of the present invention may be formed by any of a number of known technical processes allowing the manufacture of a multilayer molded container (10) having a molded inner layer (20) and a relatively thick outer layer (24), molded in HDPE plastic. . The container may advantageously be prepared by extrusion molding or blow molding.

In one embodiment, the multilayer container 10 is formed via a blow molding operation involving a multilayer preform 34, as generally described in FIG. 2. Although not a required appearance, preform 34 may include a neck flange 30 (for handling purposes) and external threads 32 (for holding a lid) which correspond to the same appearances shown in FIG. 1. After blow molding the container 10 as shown in FIG. 1, but some time before the filling operation, the inner surface (22) of the inner layer (20) of the container (10) is carbon treated, as discussed further below.

In a first configuration, as shown in fig. 2, a preform (34) or end container is produced, and, by extrusion molding, an inner layer (20 ') having an inner surface (22'), and, by injection molding, an outer layer (24 '). ). The inner layer (20 ') and the preformed outer layer (24') (34) correspond to the inner layer (20) and the outer layer (24) of the container (10). Extrusion of the preform's inner layer 20 'enables the manufacturer to produce a thinner layer than is generally possible using conventional injection molding or co-injection processes. For example, the inner layer of an extrusion molded multilayer preform (34) may be made as thin as 15-20 mils (0.381 mm to 0.508 mm) or less. In contrast, it is difficult or even impossible to make practical by injection molding an inner layer having a comparable thickness profile. Further, an extrusion or co-extrusion process allows the manufacturer to readily vary the thickness of material being extruded over the length of the extrudate. Variations in inner layer thickness are desirable for a variety of reasons including aesthetics, material use efficiency, reduced costs, and varying strength requirements.

The outer layer 24 'of the preform 34 is formed of HDPE and according to the present invention is substantially thicker than the inner bed 20'. The outer layer 24 'may be injection molded or compressed, or co-extruded onto the inner layer 20'. Such overlapping molding processes further permit the formation of a neck flange (30) and external threads (32).

In a second embodiment, shown in fig. 3, a multilayer preform (34) is produced by thermoforming a thin sheet of plastic material, and forming such a sheet into what will be the inner layer (20 ') having an inner surface (22') of it from the preform (34). . The thermoforming process allows the formation of a preform (34) with a very thin inner layer (20 '). In fact, minimum wall thicknesses of 3 mil (0.0762mm) or less are possible. As a result of an extruded inner layer 20 ', once the inner layer 20' of the preform 34 is formed, the outer layer 24 'of recycled plastic may be molded by injection or compression onto the layer. (20 ') to provide a multilayer preform (34). Fig. 3 is a representative example of a preform (34) formed with a thermoformed inner layer (20 ') and HDPE injection molded outer layer (24').

A multilayer container may then be blown using conventional blow molding operations, or a co-extruded end container obtained directly. Due to the preform (34) which will be ground and "polished" during a subsequent blow molding process, the thickness of the preform (34), portions corresponding to those similar portions of the blown container, will be inherently slightly larger. In fact, the thicknesses of the various portions of the preform (34) are typically designed to account for the amount of grinding and circumferential expansion required to form the final desired norecipient thickness profile (10). For clarity hereinafter, containers having inner and outer layers (20,24) that have not been carbon treated should be distinguished from containers (10) on which the inner surface (22) has been carbon coated.

After a container having an inner layer (20) and an outer layer (24) produced, a carbon coating is formed on at least a portion of the inner surface (22) of the inner layer (20). The carbon coating 26 does not have to be immediately applied to the container, however it is generally more efficient to apply the coating 26 promptly after the container has been blown and within an appropriate temperature profile.

In a preferred embodiment, the multilayer containers are removed from a conventional high speed rotary molding machine and subsequently transferred, directly or indirectly (i.e. via an intermediate handling step), to an apparatus for applying a carbon coating (26) to the containers. In high speed production applications, the carbon coating apparatus will also typically be rotary type. One example of such an apparatus that can be used to apply carbon coating to the inner surface 22 of the container 10 is that available from Sidel of Le Havre, France, and is commercially traded under the brand name "ACTIS".

A method for carbon coating multilayer containers (10) is described in more detail below. According to a preferred method of carbon coating the inner surface (22) of the container (10), conventional carbon coating or rotary tendokinemic carbon treatment apparatus and a central vertical axis are provided. The carbon coating apparatus generally rotates about its central vertical axis in a first rotational direction, e.g. counterclockwise, at a reasonably high rotational speed. A blow molding machine, or other rotary container transfer mechanism, generally arranged in close proximity to the carbon coating apparatus serves as the source of containers for subsequent carbon treatment. For ease of transfer, the rotary container transfer mechanism rotates in a direction opposite to the rotary direction of the carbon lining apparatus, for example clockwise, and the multilayer containers (10) are mechanically crimped from the mechanism of transferring containers to the lining apparatus. carbon. Although not required for the practice of the present invention, the container (10) preferably includes a neck flange (30) or other physical means to at least partially support the container (10) during the mechanical transfer process.

As the containers (10) are transferred from the transfer mechanism to the carbon coating apparatus, the containers (10) are preferably held by the upper portion (12) in a "standing" orientation with the opening (13) generally looking upwards. If desired, vacuum may also be generated and used to support or partially support the container (10). During the transfer process, the individual containers 10 are received by a receiving mechanism that is part of the carbon coating apparatus. The receiving mechanism rotates about the central axis of the carbon coating apparatus, grasps or holds the container and seals the opening (13) of the upper portion (12) of the container, many similar to a lid. When properly positioned over and abutting at aperture 13, the receiving mechanism produces a tight seal to seal over the container.

The receiving mechanism includes at least two openings positioned above the container opening (13) which are used for the introduction and removal of gases from the interior of the container. A first opening in the receiving mechanism is in communication with a vacuum source, such as a vacuum pump.

After the receiving mechanism has securely sealed the opening (13), the air within the container is discharged through the first opening by means of a vacuum. It is desirable that the degree of vacuum decay within a range of about 10 2 to 10 5 torr, so as to shorten the discharge time for a vacuum and thus necessarily save energy. With a low vacuum of more than 10 2 torr, impurities in the container are greatly increased; on the other hand, with a high vacuum of less than 10 5 torr increasing time and higher energy are required to discharge the air from the container.

Once the air inside the container has been evacuated, the container is subsequently filled or "charged" with a pure, undiluted gas that will be used to form the carbon coating (26). The crude gas flow rate is preferably within a range of about 1 to 100 ml / min.

Preferably, the diffusion of the crude gas into the container is increased by providing it with an extension such as a tube having a plurality of blow openings. According to one embodiment, an extension enters the container (10) through the second opening some time after the opening (13) is sealed and the extension extends from about 24.5mm to 50.8mm (1, Oin - 2, 0in) of the lower portion of the container.

The gas may be composed of aliphatic hydrocarbons, aromatic hydrocarbons, oxygen containing hydrocarbons, nitrogen containing hydrocarbons, and others in a gaseous or liquid state at an ambient temperature. Benzene, toluene, o-xylene, m-xylene, p-xylene and cyclohexane each one having six or more than six carbons is preferred. The gas may be used singly, but a mixture of two or more than two types of pure gases may be used in the dilute state in gasiner such as argon or helium.

At some point after the container has been received by the carbon coating apparatus, the container is inserted into a cylinder or other void provided to accommodate the container. In the preferred embodiment, the carbon lining apparatus includes a plurality of hollow cylinders rotating in the same direction as, and in sync with, the receiving mechanism. It is even more preferred that the receiving mechanism that holds and seals the opening (13) of the container also functions to cover the cylinder.

After the gas supply is inside the container, energy is supplied to the container from a high frequency electrical power source such as a microwave produced by device. The impression of the electric power generates plasma, and causes ionization by extreme molecular excitation and a carbon coating (26) formed on the inner surface (22) of the container. While the above method shows a process to form a carbon coating (26) on the surface inside a container, other conventional methods can also be used successfully. For example, the plastic container could otherwise be inserted and accommodated within an external electrode and have an internal electrode positioned within the container. After the container is evacuated and charged with gas supplied through the internal electrode, electrical power is supplied from the high frequency electrical source to the external electrode. The electrical power supply generates plasma between the external electrode and the internal electrode. Because the inner electrode is grounded, and the outer electrode is isolated by the insulating member, a negative autobias is generated over the outer electrode, so that the carbon film is formed evenly over the inner surface of the outer electrode container.

When Ipasma is generated between the outer electrode and the inner electrode, electrons are accumulated on the inner surface of the isolated outer electrode to negatively electrify the outer electrode to generate negative autobias on the outer electrode. At the external electrode, a voltage drop occurs because there is accumulation of electrons. At this time, carbon dioxide as a carbon source in the plasma, and positively ionized carbon source gas is selectively collided with the inner surface (22) of the container that is disposed along the outer electrode, and then carbons close to each other. others are attached together in this manner to form hard carbon film comprising a noticeably dense coating on the inner surface (22) of the container.

The thickness and uniformity of the carbon coating (26) can be varied by adjusting: the high frequency output; the norecipient gas pressure; the flow rate for charging the container with gas; the time period during which plasma is generated; o Autobias and type of primary materials used; and other similar variables. However, the thickness of the carbon coating (26) is preferably within a range of 0.05 to 10μπι to obtain effective permeation and / or absorption suppression of the low molecular weight organic compound and the increased gas barrier property, in addition. excellent aoplastic adhesion, good durability and good transparency.

Fig. 4 shows an elevational view of a further configuration of a container 100 constructed in accordance with the principles of the present invention. The container (100) typically includes an upper wall portion (112), including an opening (113); an intermediate sidewall portion (114) positioned below the upper wall portion (112); and a base portion (116) positioned below the intermediate sidewall portion (114). The base portion 116 is adapted to support the container 100 either dependently, ie where another object such as a base cup (not shown) is used, or independently, ie where no other object is required for keep the container "standing" on any flat surface. In a preferred embodiment, the container 100 is supported by a free base formed by an internal depression 118 as shown in FIG. 4

With reference to fig. 5-7 showing enlarged detailed views of the areas 100A, 100B and 100C respectively of FIG. 4, container 100 includes a molded outer layer 120 having a vertical length, an inner surface 122, an outer surface 123, and a verticalcentral B-axis. The inner surface 122 of the molded outer layer 120 is at least partially coated with a thin layer or carbon film 124 as in the configurations of FIGS. While complete encapsulation of the layer 120 within the carbon layer 124 is preferred, it may not be required for particular applications. It is preferred that the molded outer layer (120) is substantially as large as the carbon layer (124) and to provide structural support for the container (100).

The molded outer layer 120 is the desired HDPE plastics layer, although it may contain other materials as described above. If desired, the molded outer layer may be 100% HDPE plastics material.

It is particularly desirable to blend small amounts of barrier materials and / or oxygen scavengers or HDPE reactive materials as discussed in FIG. 1. For example, less than 5 wt.% Saran, ethylene vinyl alcohol (EVOH) copolymers and acrylonitrile copolymers such as Barex. In addition, the present invention may readily use ultra-low intrinsic viscosity (IV) material, ie material having an (IV) of less than around 0.60or 0.55. These materials are often white or off-white in color. A significant advantage of the present invention is the ability to process "in-process" scrap simply and efficiently even with materials as mentioned above.

The inner surface (122) of the outer layer (120) is coated with a thin carbon layer (124) which provides enhanced barrier properties to the container (100). Carbon coating configurations, characteristics and preparation 124 have been described above with respect to FIG. 1 and this also applies to the configurations of fig. 4 - 7.

The molded outer layer has a wall thickness, taken along its vertical length, which is in the range of 6 to 23 mils (0.1524mmaté 0.5842mm). As shown in fig. 5-7, the thickness of the outer layer may also be separately and independently varied along its vertical length, as with the outer layer 24 of FIG. 1. In the same manner as the outer layer 24 of FIG. 1, because the molded outer layer is comprised of a desired and less costly HDPE plastic material that should not directly contact the contents of the container (100), a less costly material may be used to form the container volume including a number of the integrated structural components for the container. , such as flanged neck (126) and outer threads (128) shown in nafig. 4. The carbon coating provides protection for the contents of the container.

Similarly, the inner carbon lining can be readily varied as the thickness varies along the vertical length of the container. Desirably, however, for convenience, a substantially uniform carbon coating is provided.

The configurations of fig. 4-7 offer the significant advantages of the present invention described with respect to FIGS. 1-3.

The container of fig. 4-7 may be formed by any of the many known processing techniques that permit the manufacture of a single layer or multilayer in molded containers as described for FIG. 1. In one embodiment, the container 100 is formed via a blow molding or extrusion operation. The container 130 as generally seen in FIG. 8 may be the extruded molded end container or a preform. Although not a required appearance, a flanged neck 132 may be provided (for handling purposes) and external threads 134 (to secure a closure), which correspond to the same appearances seen in FIG. 4. If a blow mold is employed, after blow molding the container to form the final container 100, a configuration of which is shown in fig. 4, but some time before the filling operation, the inner surface (122) of the container is carbon treated as already detailed above.

In a configuration shown in fig. 9, a container preform (140) is produced by extrusion by molding a preform or end container (140) with a body (146) and a base (148), neck flange (142), and external threads (144). An extrusion process allows the manufacturer to readily vary the thickness of material being extruded over the extruded length. Variations in preform thickness are desirable for a number of reasons including aesthetics, efficient material use and reduced costs, and varying strength requirements.

The container or preform (140) is based on HDPE plastic material which, as already indicated, is a particular advantage of the present invention.

In the configuration of fig. 8, a preform or final container (130) is produced by thermoforming a thin sheet of plastics material and forming a tab into what will be the preform (130); or injection or compression to shape the preform (130). Thus, the preform of fig. 8 may include a flanged neck (132) outer erosion (134), body portion (136) that will be the body portion of the container and the base portion (138) that will be the base portion of the container.

The container may then be blown if conventional blow molding operations are desired as described above.

After the final container is formed, a carbon coating is formed on at least a portion of the inner surface 122 of the container 120 and preferably on the entire inner surface as described above with FIG. The carbon coating 124 does not need to be immediately applied to the container, however, it is generally more efficient to apply the carbon coating as soon as the intermediate container has been blown and within an appropriate temperature profile.

The container of fig. 4 offers significant advantages over those of FIG. 1. The basics of the container is a monolayer material which can be readily processed by conventional means. In addition, inexpensive HDPE base material can be readily mixed with other materials and due to the internal carbon coating does not come into contact with the contents of the container and the contents are well protected. Barrier properties are readily obtainable and the contents of the container are not impacted by adverse tastes and flavors. Furthermore, the container of the present invention eliminates the need for a separate barrier or a blank cover. The small amount of internal carbon coating does not adversely affect recycling, and colored materials can be readily used to provide a desirably colored container, for example, the outer layer can be easily colored to a commercially desired color.

The container of fig. 4 offers the significant advantages of a mono-layer container with properties designed as desired, barrier resistance and low cost. Thus, processing is significantly easier than with multilayer containers since working with a single layer material without the need for wrappers and complicated co-injection processing. In addition, the recycled plastic can be "blended" with other materials to readily obtain special properties while maintaining the use of desirably low cost recycled plastic. For example, one can standardize the product to achieve desirable characteristics while using a recycled material and a single layer material.

The internal carbon coating is simple to apply and is completely thin and yet prevents the migration of adverse flavors and taste into the contents of the container. It is particularly desirable to use a variety of colors for HDPE plastic such as a cormbar. It would be highly desirable to use such a container as in the present invention with a well-combined color and for juice-like products. As an alternative, there could be a blend of heat resistant plastic or other materials with HDPE to achieve highly desired characteristics.

While certain preferred embodiments of the present invention have been described, the invention is not limited to the water-drawn and shown illustrations which are intended to be merely illustrative of the best modes of conducting the invention. A person or a regular expert in the art will imagine certain alternatives, modifications, and then variations will occur within all techniques of this invention; but such alternatives, modifications, and variations will remain within the spirit and comprehensive scope of the appended claims.

Claims (18)

1. Molded container (100) including an upper wall portion (112) having an opening (113), an intermediate sidewall portion (114) positioned below the upper wall portion (112), and a base portion (116) positioned below of the intermediate sidewall portion (114) and adapted to support the container, said container further comprising: a first molded layer (120) having an inner surface (122) and an outer surface (123) and formed of high density polyethylene; a carbon coating (124) formed adjacent to the inner surface (122) of the first layer (120) and adhered thereto substantially equal to the first layer (120), said carbon coating (124) having a thickness of less than 10 microns characterized in in that the carbon coating (124) has a thickness that varies along the vertical length of the container and the thickness of the inner carbon layer (124) varies independently from the first layer (120). Container according to claim 1, characterized in that it can be extruded molded and blow molded. Container according to claim 1, characterized in that said first layer pellet (120) has a thickness of 6 to 23 mils, and that the carbon coating (124) has a thickness of 0.05 to 10 microns. Container according to claim 1, characterized in that the thickness of the first layer (120) varies so that the intermediate sidewall portion (114) is thinner than the upper wall portion (112) and than the base portion (120). 116). Container according to claim 1, characterized in that it includes a barrier-like material added to the first layer (120). Container according to claim 1, characterized in that the carbon pellet coating the inner surface (122) of the container (100) is provided by at least one gaseous hydrocarbon. Container according to claim 1, characterized in that said coating carbon is amorphous. Container according to claim 1, characterized in that said coating carbon has one of generally uniform thickness, said container (100) having a thickness that varies along the vertical length of the same container. Container according to claim 1, characterized in that it includes at least one of the upper portions of the container including a support flange (126) and the base portion (116) including an inwardly directed portion of the container (100). Container according to claim 1, characterized in that the first layer is colored. Container according to claim 1, characterized in that it is intended for non-carbonated beverages. Container according to claim 1, characterized in that the first layer (120) contains oxygen scavenging material. Container according to claim 1, including a second layer (24) adjacent to the first layer (20), characterized in that said second layer (24) is adjacent to at least one of the surfaces: inner of the first layer and external of the first layer. Container according to claim 13, characterized in that the second layer (24) is formed of a plastics material comprised of a resin selected from the group consisting of polyethylene resins, polypropylene resins, polystyrene resins, cycle copolymer resins -olefins, polyethylene terephthalate resins, polyethylene naphthalate resins, ethylene vinyl alcohol copolymer resins, poly-4-methylpentene-1 resins, depolymethyl methacrylate resins, acrylonitrile resins, polyvinyl chloride, polyvinylidene chloride deresins, styrene nitrile acryl resins, butadiene styrene nitrile resins, polyamide resins, polyamide imide resins, polyacetal resins, polycarbonate resins, terephthalate resins polybutylene, ionomer resin, polysulfone resin, polytetrafluoroethylene resin, and combinations of two or more of such resins. Container according to claim 13, characterized in that at least one of the first (20) or second layers (24) has a thickness that varies along its vertical length. Container according to claim 13, characterized in that the thicknesses of the first layer (20) and the second layer (24) are controlled with respect to each other. Container according to claim 1, characterized in that the thickness of the carbon coating (124) is smaller than the carbon coating (124) is less than 1/10 000 of the total weight of the container. Container according to claim 1, characterized in that the high density polyethylene has a density of 0.940 gr / cm3.